The New York Times describes him as a "cleric known for his fiery oratory, [who] had recorded impassioned speeches for Bin Laden after Sept. 11, in which he praised the attacks and promised that future attacks would be carried out."

As NPR's Joel Rose reports: "The biggest surprise of the trial came when Abu Ghaith testified in his own defense. He admitted traveling to meet with bin Laden in a cave in Afghanistan. But Abu Ghaith pleaded not guilty and denied knowing any details of al-Qaida's terror plans."

In his testimony, the former al-Qaida spokesman said that he wasn't aware of the Sept. 11 attacks until he was told by bin Laden soon after they took place. He said it was only then that the al-Qaida leader tapped him for the job of spokesman for the group, asking that he "deliver a message to the world."

He testified that in response to bin Laden's request, he begged him, "Kindly spare me this mission."

When asked by bin Laden what he thought would happen after the attacks in New York and Washington, D.C., Abu Ghaith said he predicted that America "will not settle until it kills you and topples the state of Taliban."

"You're being too pessimistic," he quoted bin Laden as saying.

Abu Ghaith's defense team was rebuffed when it sought to introduce written testimony from self-described 9/11 mastermind Khalid Sheikh Mohammed, who is currently in detention at Guantanamo Bay. Mohammed said Abu Ghaith was "an eloquent, spellbinding speaker" but played no military role in the group.

The Times says:

"The jury returned its verdict on its second day of deliberations in the trial, which had entered its third week in United States District Court in Manhattan. Mr. Abu Ghaith was convicted of three counts: conspiracy to kill Americans, for which he could face life in prison; and providing material support to terrorists, as well as conspiring to do so, counts that each carry maximum terms of 15 years."

Update at 6:55 p.m. ET:

U.S. Attorney Preet Bharara issued a statement to NPR on the conviction of Sulaiman Abu Ghaith:

"He was more than just Osama bin Laden's propaganda minister. Within hours of the devastating 9/11 attacks Abu Ghaith was using his position in al-Qaida's homicidal hierarchy to persuade others to pledge themselves to the cause of al-Qaida by murdering more Americans," Bharara said.

"Abu Ghaith received a fair trial, after which a unanimous jury rendered its verdict, justly holding him accountable for his crimes," he said.